Scaffold.



F. MAGNUSON.

sGFFoLD.

APPLICATION FILED JUNE 16, 1910.

Patented Aug. 15, 1911.

2 SHEETS-SHEET 1.

M lf wle Wawy@ F. MAGNUSON.

SGAFFOLD. x

APPLICATION FILED JUNE 16, 1910.

Patented Aug. 15, 1911.

2 SHEETS-SHEET 2.

UNrTED STATES 'PATENT oFFioE.

FRANK MAGNUSON, OF SOUTH CHICAGO, ILLINOIS.r A,

SCAFFOLD.

Siiecication of Letters Patent. Patented Aug'. 15, 1911. ApplGatOn ledTulle '16, 1910. Serial N0. 567,257.- Y

To all whom it may concern:

Be it known that I, FRANK MAGNUSON, a citizen of the United States,residing at South Chicago, county of Cook, and State of Illinois, haveinvented certain new and useful Improvements in Scaolds, of which thefollowing is a specification.

My .invention relates to adjustable scaffolds and has for its object theproduction of a device of this character which` will be of durable andeconomical construction and reliable and efficient in operation.

Other objects will appear hereinafter.

l/Vith these objects in view my invention consists in a scaffoldcharacterized as above mentioned and in certain details of constructionand arrangement of parts all as will be hereinafter fully. described andmore particularly pointed out in the appended claim.

My invention will be more readily understood by reference to theaccompanying drawings forming a part of this specification, and inwhich,

Figure 1 is a side elevation of a scaffold embodying the preferred formof my `invention, Fig. 2 is a top plan view thereof, Fig. 3 is anenlarged sectional top plan View of a portion of the scaffold, Fig. 4 isan. end elevation of the device, Fig. 5 is a transverse section taken online -w of Fig. 4, and Fig. 6 is a detail. elevation of a portion of theconstruction shown in Fig. 4.

Referring now to the drawings 1, l and 1 indicate parallelly extendingcoplanar supporting devi es which are suitably spaced so as to supportelongated platform boards 2 upon the upper elongated body portions 3thereof. The members 1, 1 and 1 are of identical construction so thatthe description of one, which will be set forth in the following, willapply to each of the others. Upon the under side of the body 3, at therespective ends thereof, are provided rectangular bearing frames orhangers 4 and 4. Journaled. in each of said hangers between thevertically and parallelly extending bar portions 5 thereof is a shaftyG'upon which is fixed a substantially centrally positioned reel or drum7, a gear 8, and a ratchet wheel 9, said gear and ratchet being arrangedat either end of said reel adjacentthe bars 5.

'Secured to and coiled upon the reels 7 are cables 10, the free endsthereof projecting upwardly through registering slots 11 and 12 providedrespectively in the body 3 and platform boards 2, the upper extremitiesof said cables' being provided with attaching devices 13 whereby thesame may be secured to supporting-'beams 14 or other suitable supportingrstructure in conjunction with which the scaffold is employed. j i, 15indicates a shaft which is journaled in coaxial bearing straps 16provided upon corresponding sides of the bars 5 adjacent the upper endsthereof. Fixed to said shaft are pinions 17 which mesh with the gears 8,and rotatably and slidably mounted upon said shaft adjacent the pinions17 are journaled pulleys 18, the latter being of diameters such that thesame are disposed tangentially with the Vertical plane of the slots 11and 12, and whereby said pulleys areadapted to serve as guides for thecables 10 to properly direct the same for passage through the slots 11and 12, such pulleys being so mounted that, as the cables are coiledupon or uncoiled from the reels 7 the formerv will slide'upon the shaft15 to accommodate the changing positions of the free ends of saidvcables,`,19 indicates spring pawls adapted to coact with the ratchetwheels 9 to normally prevent retrograde rotation thereof and henceuncoiling rotation' of the reels 7. Flexible cords 20 are secured attheir lower extremities to the free ends of the pawls 19, the sameextending upwardly therefrom through the slots 11 and 12 and beingprovided 'at their upper extremities with hand rings 21 whereby saidpawls may, from a position upon the platform, b e elevated to disengagethelratchet wheels 9- Itotatably mounted onthe outer end of the shaft 15is the lower endof an operatingl hand lever 22, the latter normallyprojecting upwardly to a substantially vertical position so that thesame, may be readily engaged from a position upon the 4platform and bemanually oscillated. The lower end of said lever is of forked form, asclearly shown in Fig. 4 and fixed to the extremity of the shaft 15 at aposition thereon between the fork arms is a ratchet wheel 23.

Carried by said lever is a spring pawl 24` adapted normally to coactwith the ratchet wheel 23 in order to effect positive rotation of theshaft 15 and hence coiling of the cables 10 upon the reel 7 when saidlever `is oscillated. A cord 25 is secured at its lower end to the freeend of saidwpawl, the

same extending through guide eyes 26 "in the outer side of the lever toa position in- Which the same may be engaged Aif desired`- whenoperating said lever, in order to effect the disengagement of said pawlwith the ratchet 23. An ear 27 projecting from the outer extremity ofthe body 3 serves as a stop lfor the lever 22 to limitupward or rearwardoscillation thereof. The arrangement is such, as will be observed, that,in order to eect the elevation of the'nscaf'fold, itis only required tosimultaneously oscillate levers 22 of the various supporting devices l,such operation effecting, as before described, the winding of the lowerends ofthe cables 10 upon the reels 7, and hence the correspondingelevation yof'the devices l and the platform 2. Locking of the scaffoldin any position to which it may be elevated is automatically effectedthrough the medium of the pawls 19 and"24;,'the latter, i 'through theirown resiliency, normally remaining in constant engagement with theratchet Wheels 9 and 23. In order to descend it is only required toalternately disadjacent the outer ends thereof. The up@ per ends of saidposts are formed into eyes through whichextend and to which-'is secureda rope 29, the latter being adapted to serve as a guard rail for thoseworking upon the platform.

A device of theconstruc'tion shown and described is perfectly reliableand safe in operation, is of durable construction and the samefmay beoperated in order to raise or lower the same with ease and readiness.

. While I have shown what `I deem to be the preferable form of mysca'old I do vnot wish to be limited thereto as there might be variouschanges made in the details of construction and arrangement of partsdescribed without departing from the spirit of the inventioncomprehended within the scope of the appended claim.

Having described my invention what I claim as new and desire to secureby Letters Patent is:

A scaffold comprising a platform; sup

porting means for each end of said platform, said means comprising anelongated body extending transverselyr of said platform; hangers at theunderside of said body at each end thereof; coaxial reels mounted insaid hangers; pawl and ratchet devices arranged to prevent unwinding ofsaid reels; a shaft mounted in said hangers and extending longitudinallyof said body above said reels, there being elongated slots in saidsupport above said shaft'and reelsya gear connection between saidshaftxand each of said reels; grooved pulleys loosely .mounted on saidshaft under said slots; supporting cables passed through-said slots,over said pulleys and coiled on said'reels; andlmeans for operating saidshaft, substantially as described.

In testimony whereof I have signed my name to this specication` in thepresence of two subscribing witnesses. v

FRANK MAGNUSON.

Witnesses:

ARTHUR A. OLsoN, JOSHUA R. H. Po'r'rs.

